Blanket bar and adapter bar assembly for printing blanket

ABSTRACT

An assembly for attaching a printing blanket on a press cylinder of an offset printing press. An adapter bar and blanket bar are provided with cooperating features which provide interlocking engagement for quick and easy mounting by way of a quick release locking means.

O United States Patent n51 3,675,573 Hawks [451 July 1 l, 1972 s41BLANKET BAR AND ADAPTER BAR 1.578.736 3/1926John...............................v..101/415.l ASSEMBLY FOR PRINTINGBLANKET 2,694,976 11/1954 Huck..... |0l/41$.l 1,215,344 2/1917C1ark..... ..l0l/415.l lnvenlofl "mks, Des 2,046,122 6/1936 non/41s.! xAsslgnee: Rubens Porter Inc. Primary Examiner-Clyde l. Coughenour [22]Filed: Sept. 1, 1970 Attorney-Molinare. Allegretti. Newitt 8: Witcofi"[2|] Appl. No.2 68,728 57 BS An assembly for attaching a printingblanket on a press (52] US. Cl .1..l0l/4l5.l, 101/378 cylinder ofanoffset printing press. [51] Int. Cl. r v ..B4ll'27/l2 An ada pter barand blanket bar are provided wlth cooperatmg [581 Field 4 features whichprovide interlocking engagement for quick and easy mounting by way of aquick release locking means. [56] References Cited 3 Claims, 5 Drlwlngfigures UNITED STATES PATENTS l,39|,ll7 9/l921 Huebner ..10l/415.1

BLANKET BAR AND ADAPTER BAR ASSEMBLY FOR PRINTING BLANKET BACKGROUND OFTHE INVENTION This invention relates to an assembly of an adapter barand a blanket bar for securely attaching a rubber printing blanket to apress cylinder of an offset printing press.

Printing blankets used on offset printing presses comprise an elongatedsheet of material having a heavy cotton backing and the upper facethereof being coated with rubber or synthetic material to provide asurface which is utilized to pick up the ink image from an ofi'set plateor other image carrier for transfer onto a sheet of paper or othermaterial to be printed. The leading and trailing edges of the blanketare each provided with what are known as blanket bars, with portionsengaging opposite surfaces of the end portion of the blanket. The presscylinder is provided with a suitable recess or opening in its peripheryinto which the ends of the blanket with the blanket bars attached areinserted and firmly attached. Mounted within the recess of the presscylinder are suitable adapter bars into which the blanket bars, at theopposite ends of the blanket, are firmly secured. The adapter bars areusually associated with suitable mountings for adjustment of the adapterbars, to take up slack in the blanket and insure a firm fit of theblanket against the surface of the press cylinder. Heretofore, blanketbars were formed of elongated strips of metal or other rigid materialfirmly attached to the opposite surfaces of the blanket, adjacent theends thereof. Usually such strips are secured in place by bolts, screwsor rivets, and/or by the use of various types of adhesive, or any othersuitable means of attachments. The matter of attaching such strips tothe ends of the blanket are time consuming and result in numerousdisadvantages.

More recently a new type of blanket bar has been devised, and which isof generally V shape in cross-section, comprising a pair of elongatedleg portions, interconnected at corresponding edges, for embracing theentire end portion of the blanket. Such recent types of blanket bars areusually provided with a plurality of ridges or sets of prongs, extendinglongitudinally of the bars, on the inner surface of the legs thereof,and which serve to bit into the blanket when the bar embraces and iscompressed around the end portion of the blanket, for firmly grippingand securing the blanket bar to the end of the blanket. The ridges orprongs on the inner surface of one of the legs are offset with respectto the ridges or prongs on the inner surface of the other leg to providea firm interlocking grip on the blanket. Such types of blanket bars areformed as extrusions of aluminum or other suitable metal and are capableof being quickly and easily attached to the blanket. Blanket bars ofthis general category are disclosed in Kirkpatrick US. Pat. No.3,296,673,dated Jan. 10, I967.

More particularly, the present invention is directed to a novel assemblyof an adapter bar and blanket bar, provided with cooperating featureswhich provide interlocking engagement of the bars and which pennitsquick and easy mounting of a blanket bar in an adapter bar for securingthe blanket in proper relation to the outer surface of the presscylinder.

Another object is to provide a novel assembly of an adapter bar and ablanket bar which permits quick and easy mounting or demounting of theblanket bar with respect to the adapter bar, together with fasteningmeans for quickly and easily locking the blanket bar in operativeposition in the adapter bar or for permitting quick and easy removal ofthe blanket bar from the adapter bar to provide quick and easy placementof the blanket in proper operative relation to the surface of the presscylinder or removal therefrom.

A further object of this invention is to provide means for visuallyindicating whether the blanket bar is in locked or unlocked positionwith respect to the adapter bar when the two bars are assembled.

Other objects and advantages of this invention will be apparent from thefollowing description, taken in connection with the accompanyingdrawing.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an enlarged, fragnentary,perspective view of an amembly of an adapter bar and blanket bar, with aprinting blanket secured to the blanket bar and embodying the presentinvention.

FIG. 2 is a sectional view, taken at line 2-2 on FIG. 1, showing theadapter bar and blanket bar, with the blanket attached to the latter,positioned in cooperating relation, with the fastening means shown in anunlocked position.

FIG. 3 is a sectional view similar to FIG. 2 but showing the fasteningmeans in operative position for positively and securely locking theblanket bar in the adapter bar.

FIG. 4 is a fragmentary, longitudinal view, part in section. through theadapter bar, taken at line 4-4 on FIG. 2. with the blanket bar omitted.

FIG. 5 is a fragmentary perspective view of the blanket bar in itsinitial position, preparatory to receiving the end of a blanket.

DESCRIPTION OF THE PREFERRED EMBODIMENT As may be seen in the drawing,the assembly comprises an adapter bar A and a blanket bar B mounted inthe adapted bar and with one end of the printing blanket, indicatedgenerally at C, secured to the blanket bar. The adapter bar as shown isof a design which is especially adapted for use with certain well-knownoffset printing presses. The adapter bar may be of differentconfiguration and dimensions for use in other different types ofpresses. It is to be understood that the adapter bars and blanket barsusually are of a length corresponding to the width of the printingblanket with which it is to be used. Widths and lengths of printingblankets for different models of presses varies substantially, andusually are in the range of 22 inches to inches wide.

The adapter bar A has a body or base 10 formed with an elongated channel12, extending from end to end of the body. The channel has a flat bottomwall 14, with the forward edge defined by an upstanding abutment l6, andits rear edge defined by an upstanding wall 18 which continues into aforwardly extending lip portion 20. The inner surface of the lip portionis spaced from the bottom wall [4 which together with the wall 18defines a generally U-shaped portion 22 of the channel. The innersurface of the abutment 16 is shaped to provide a V-shaped tongue orridge 24, preferably extending the full length of the adapter bar, withthe opposite surfaces of the tongue defining an angle in the generalrange of 45.

The outer shoulder of the body 10 of the adapter bar A, is fonned withappropriate slots or openings 25, for receiving fastening elements forsecuring the adapter bar to its mounting in the reces of the presscylinder.

Mounted in the U-shaped portion 22 of the channel, against the innersurface of wall 18, are a plurality of longitudinally spaced apart,compressible, resilient pads 26, formed of sponge rubber or othersynthetic material. The surface of the pads, ad'acent said wall 18, areprovided with a suitable coating of adhesive for securing them inposition in the channel. The pads may be of small size, in the range ofl inch long and may be spaced suitable distances apart, such about I 2inch.

The blanket bar 8 may be formed of various material and various shapesand as shown in the drawing the bar is formed as an extrusion ofaluminum or other suitable material and initially is of generallyV-shaped formation, including a pair of inter-connected spaced apartlegs 30 and 32, with the spacing of the legs at the juncture beingsuficient to accommodate the hickness of the end of the printing blanketC. The inner surfaces of the legs 30 and 32 are provided with amultiplicity of longitudinally extending ridges 34, of generallyV-shaped cross section, with the ridges on one of the legs beingstaggered or offset with respect to the ridges on the other leg so thatwhen the blanket C is placed into the blanket bar and the legs arecompressed together, the two sets of ridges serve to firmly grip andbite into the blanket material, as seen in FIG. 2 of the drawing, forpositively gripping and attaching the blanket bar 8 to the blanket C.Preferably, although not absolutely necessary, the inner surfaces of thelegs 30 and 32 are coated with a suitable adhesive to insure a permanentgripor bond with the blanket. The outer free edge of the lower leg 32 ofthe blanket bar B is formed with a longitudinally extending V-shapedgroove 36, with opposite main surfaces of the groove positioned at anangle of approximately 45 to each other.

When the blanket bar B, with the blanket C secured thereto, is beingmounted in the adapter bar A, the closed end of the blanket bar isinserted into the U-shaped channel portion 22, in contact with theresilient pads 26, to compress them sufficiently so that the forward endof the lower leg 32 of the blan' ket bar clears the tongue 24 of theabutment l6 and permits seating of the blanket bar B against the flatbottom surface 14 of the channel 12 of the adapter bar. The resiliencyof the pads 26 serves to urge the blanket bar 8 in a forwardly, oroutwardly direction so that the V-shaped groove 36 is moved and guidedinto cooperative engagement with the V-shaped tongue 24 of the abutment16, for locking the forward edge of the assembly together. In thisposition, the upper surface of the leg 30 of the blanket bar, adjacentthe closed end thereof, is disposed in relatively close relation to theinner surface of the lip of the adapter bar.

Suitable fastening means is provided for quickly and easily releasablysecuring the blanket bar B, with the printing blanket C attachedthereto, in the adapter bar A. This means comprises two or morefasteners, preferably Allen Head type screws 40, mounted in threadedopenings formed in the lip portion 20, the wall 18 and the base 10 ofthe adapter bar, as seen in FIGS. 2 and 4. Each of the fastening screwsis formed with a longitudinally extending notch 42, of a length at leastequal to the distance between the under surface of the lip 20, and theflat bottom surface 14 of the channel. The depth of the notch is suchthat in one position of adjustment, as hereinafter described, the fiatbottom surface of the notch is approximately flush with the innersurface of wall [8 of the adapter bar A. The head of each of the screwsis cut to provide a flat index surface 46, which is circumferentiallyaligned with the fiat bottom surface of the notch 42 in the screw, asclearly seen in FIG. 2.

in order that the blanket bar B with the printing blanket attached maybe initially positioned in cooperative relation in the channel 14 of theadapter bar A, as seen in FIG. 2, the screws 40 must be positioned sothat their notches 42 and the flat index surfaces 46 on the heads facein the direction of the blanket bar. To securely lock the blanket bar Bin the adapter bar A, the screws 40 are rotated 180, to the positionseen in FIG, 3 of the drawings, so that the threads of the screws 40bite into the outer surface of the closed end portion of the blanket barB and forcibly urge the blanket bar forwardly for full inter-engagementof its V-shaped groove 36 with respect to the'V-shaped tongue 24 on theabutment 16 of the adapter bar, Such positive movement simultaneouslyforces the blanket bar in a downward direction and wedges the lowersurface of the V-shaped groove 36 against the under surface of theshaped tongue 24 on the abutment, to positively lock the blanket bar infixed relation to the adapter bar. It will also be apparent that thetongue and groove features on the abutment shoulder 16 of the adapterbar and the outer free end of the lower leg 32 of the blanket bar alsoinitially serve to guide and seat the blanket bar in a propercooperating relation to the adapter it will be noted from FIG. 3, whenthe screws have been rotated to securely lock the blanket bar in theadapter bar, the flat index surfaces 46 of the screws 40 are alignedwith the top edge of the outer surface of the upright wall 18 of theadapter bar to visually indicate that the bars are in locked position.Likewise when the screws are in the position seen in FIG. 2, the indexsurfaces indicate an unlocked relation of the assembly of the bars.

It is apparent that the adapter bar, when mounted in the recess of thepress cylinder, permits the blanket bar with the blanket attached, to bequickly and easily detachably secured in coo rative relation by merelyrotating the fastenin screws 40, 1E8". Thus, substantial time is savedin attac ing or detaching the printing blanket in operative relation tothe surface of the press cylinder.

What is claimed is:

1. in an assembly for attaching a printing blanket on a press cylinderof an offset printing press, comprising an elongated adapter bar formedfor attachment within a recessed portion of a press cylinder andprovided with a base having a channel extending from end to end andhaving a bottom wall with its forward edge defined by an upstandingabutment shoulder and its rearward edge defined by an upstanding wallwhich continues into a forwardly extending lip portion with its undersurface spaced from the bottom wall to form a U-shaped portion of thechannel, an elongated blanket bar having portions secured to oppositesides of a free end portion of a printing blanket and adapted to bedetachably mounted in the adapter bar to position the blanket on thepress cylinder, the inner surface of said abutment shoulder on theadapter bar being engageable by the inner edge of the underside portionof the blanket bar, the improvement comprising means carried on theadapter bar for coacting with the outer edge of said blanket bar forwedging the inner end of the underside side portion of the blanket baragainst said abutment shoulder and positively locking the blanket bar tothe adapter bar, said means comprising a threaded type headed fastenerthreaded through said lip of the adapter bar and adapted to extend, inone position of adjustment, across said U-shaped portion of the channelof the adapter bar into wedging engagement with the outer edge of theblanket bar, said fastener having a portion of its shank cut away for alength at least equal to the space between the underside of the lip andthe bottom wall of the channel, providing a flat face, which in anotherposition of adjustment of the fastener disposed substantially flush withthe inner surface of the closed end of said U-shaped portion of thechannel.

2. The construction defined in claim I, wherein the head of the fastenerbeing provided with an index feature adapted to be selectivelyregistered with a feature on the upper surface of said lip portion ofthe adapter bar to visually indicate the position or location of saidflat face of the cut away portion of the screw.

3. The construction defined in claim 1, wherein the threaded fastener isthreaded through the lip and into the base of the adapter bar.

l i i i

1. In an assembly for attaching a printing blanket on a press cylinderof an offset printing press, comprising an elongated adapter bar formedfor attachment within a recessed portion of a press cylinder andprovided with a base having a channel extending from end to end andhaving a bottom wall with its forward edge defined by an upstandingabutment shoulder and its rearward edge defined by an upstanding wallwhich continues into a forwardly extending lip portion with its undersurface spaced from the bottom wall to form a U-shaped portion of thechannel, an elongated blanket bar having portions secured to oppositesides of a free end portion of a printing blanket and adapted to bedetachably mounted in the adapter bar to position the blanket on thepress cylinder, the inner surface of said abutment shoulder on theadapter bar being engageable by the inner edge of the underside portionof the blanket bar, the improvement comprising means carried on theadapter bar for coacting with the outer edge of said blanket bar forwedging the inner end of the underside side portion of the blanket baragainst said abutment shoulder and positively locking the blanket bar tothe adapter bar, said means comprising a threaded type headed fastenerthreaded through said lip of the adapter bar and adapted to extend, inone position of adjustment, across said U-shaped portion of the channelof the adapter bar into wedging engagement with the outer edge of theblanket bar, said fastener having a portion of its shank cut away for alength at least equal to the space between the underside of the lip andthe bottom wall of the channel, providing a flat face, which in anotherposition of adjustment of the fastener disposed substantially flush withthe inner surface of the closed end of said U-shaped portion of thechannel.
 2. The construction defined in claim 1, wherein the head of thefastener being provided with an index feature adapted to be selectivelyregistered with a feature on the upper surface of said lip portion ofthe adapter bar to visually indicate the position or location of saidflat face of the cut away portion of the screw.
 3. The constructiondefined in claim 1, wherein the threaded fastener is threaded throughthe lip and into the base of the adapter bar.